1. Field of the Invention
The present invention relates generally to redundancy of base transceiver system.
2. Description of the Related Art
In general, a base transceiver largely includes a Digital Unit (DU) and a Radio frequency Unit (RU). The DU is a digital device for processing a baseband signal, and the RU is an analog device for processing an analog radio signal.
The base transceiver can be operated in a redundancy scheme or a simplification scheme. The redundancy scheme doubles a board or a unit of the DU and switches the failed board or unit. However, since the redundancy scheme increases system cost, most mobile communication base transceiver systems utilize simplified scheme with the single board or unit.
FIGS. 1A and 1B illustrate a base transceiver including DUs and RUs connected to a switch in a conventional wireless communication system.
Referring to FIG. 1A, a first DU 103, a second DU 105, a first RU 109 linked to the first DU 103, and a second RU 111 linked to the second DU 105 are connected to a switch 107. The first DU 103 and the second DU 105 are digital devices in the base transceiver for processing the baseband, and the first RU 109 and the second RU 111 are analog devices for processing analog radio signals of RF. Typically, the base transceiver includes the DU and the RU, which may be integrated as a single unit or separated by a certain distance.
When the first DU 103 and the second DU 105 are in a normal operation 101, the first RU 109 and the second RU 111 linked to the first DU 103 and the second DU 105 via the switch 107 are successfully connected to provide normal service. However, when the second DU 111 has a fault, in operation 113, the first RU 109 linked to the first DU 103 via the switch 107 continues to operate normally, but the second RU 111 linked to the second DU 105 via the switch 107 experiences a service interruption.
FIG. 2 illustrates a base transceiver service interruption when a second DU fails among DUs and RUs connected to a switch and in a conventional wireless communication system.
Referring to FIG. 2, a first base transceiver provides a service coverage 201, a second base transceiver provides a service coverage 203, a third base transceiver provides a service coverage 205, and a fourth base transceiver provides a service coverage 207. When the second DU of the second base transceiver fails, the service of the second RU linked to the second DU via the switch is interrupted, thereby interrupting the service of the second base transceiver, as identified by in 209.
As discussed above, when a main processor or channel card of a DU fails in a simplified scheme base transceiver system, an RU connected to the failed component cannot provide service, and thus, the service is interrupted.